1. Field of the Invention
The present invention relates to image processing devices, image processing methods and computer program products, and more particularly to image processing devices, image processing methods and computer program products for combining images obtained from separate-pickup to form an image at a high resolution.
2. Description of the Related Art
Conventionally a technique has been known for combining a plurality of partial images obtained from separate-pickup of an object to form an image at a high resolution.
(1) In Japanese Patent Laying-Open No. 7-264394, an image processing device is disclosed in which, when a feature point is not included in a region where two partial images to be combined overlap, the region to be picked up as the partial images is illuminated with a marker and the partial images are combined, the marker included in the partial images is used as a reference.
(2) In Japanese Patent Laying-Open No. 9-74522, an image input and reproduction system is disclosed wherein partial images obtained through pickup by a plurality of pickup elements are combined based on relative position information of the plurality of pickup elements.
(3) In Japanese Patent Laying-Open No. 9-322039, a pickup device is disclosed wherein a plurality of images are picked up by a pickup element such that portions of the plurality of images overlap, corresponding points in the picked-up plurality of images are extracted, images arranged in a horizontal direction are combined as a line, and the resulting image is sequentially output to a printer.
(4) In Japanese Patent Laying-Open No. 10-215411, a digital X-ray pickup device is disclosed wherein boundary indexes for separate areas are provided in a frame in which a pickup area is displayed, partial image is picked up such that both an object and the boundary index are picked up and the partial images are combined such that the positions of boundary indexes in the partial images match with each other.
The conventional techniques as described above, however, have the following problems.
(1) The image reading device as disclosed in Japanese Patent Laying-Open No. 7-264394 tends to be expensive because an additional structure for directing a marker is required and a light with a strong intensity must be directed to show the marker on the images clearly.
(2) The image input and reproduction system, as disclosed in Japanese Patent Laying-Open No. 9-74522, has a limit in the accuracy of combining because the combining of the partial images is based on the relative position information from the plurality of pickup elements, and the accurate combining is not allowed.
(3) The pickup device as disclosed in Japanese Patent Laying-Open No. 9-322039 cannot align the partial images when the corresponding points do not exist in the overlapping regions of the partial images to be combined.
(4) In the digital X-ray pickup device as disclosed in Japanese Patent Laying-Open No. 10-215411, a large region, which is not originally necessary as the partial image, is included in the picked-up image and the ratio of the original in the partial image is low. This problem will be described further in detail below.
FIG. 11 shows a frame used in a conventional pickup device. In a frame 200, four boundary indexes 201 are provided and an original 202 is shown placed on the frame.
FIG. 12 shows an example of partial images obtained from separate-pickup by the conventional pickup device. In FIG. 12, (A) shows a partial image 210 of an upper left portion and (B) shows a partial image 211 of an upper right portion. As shown in (A) and (B) of FIG. 12, both partial images 210 and 211 include boundary indexes 201. Hence partial images 210 and 211 include a large portion besides the original and the ratio of the necessary original portion in the partial image becomes low.
The present invention is made to solve the above described problems and an object of the present invention is to provide image processing devices, image processing methods and computer program products allowing the accurate combining of two adjacent images even when a common feature point to two adjacent images do not exist in a region where two images overlap.
According to one aspect of the present invention, to achieve the object described above, an image processing device includes: an input section to input a plurality of images obtained from a separate-pickup of an object performed such that parts of the images are overlapped; and a combining section to combine two images adjacent to each other in one of a first manner and a second manner; in the first manner, two images adjacent to each other in a first direction are combined based on overlapping regions of two images adjacent to each other in the first direction, and in the second manner, two images adjacent to each other in a second direction are combined based on overlapping regions of two images adjacent to each other in the second direction; and the image processing device further includes a controller to control the combining section according to a predetermined condition such that the combining section performs the combining in one of the first manner and the second manner.
According to another aspect of the present invention, an image processing device includes: an input section to input an image obtained from a separate-pickup of an object; a combining section to combine two adjacent images; and a controller to control the combining section such that the two adjacent images input through the input section are combined based on overlapping regions of the adjacent images if possible, otherwise two adjacent images are combined based on another image input through the input section.
According to still another aspect of the present invention, an image processing method includes: a receiving step of receiving a plurality of images obtained from a separate-pickup of an object performed such that parts of the images are overlapped; a first combining step of combining two images adjacent to each other in a first direction based on overlapping regions of two images adjacent to each other in the first direction; and a second combining step of combining two images adjacent to each other in a second direction based on overlapping regions of two images adjacent to each other in the second direction; wherein the first combining step is performed first and then the second combining step is performed when the plurality of images can be combined at the first combining step whereas the second combining step is performed first and then the first combining step is performed when the plurality of images cannot be combined at the first combining step.
According to a further aspect of the present invention, an image processing method includes: a first receiving step of receiving a plurality of images obtained from a separate-pickup of an object performed such that parts of images are overlapped; a first combining step of combining two adjacent images based on overlapping regions of the two adjacent images; a second receiving step of receiving an image including a feature point common to the two adjacent images when the two adjacent images cannot be combined at the first combining step; and a second combining step of combining the two adjacent images based on the image received at the second receiving step.
According to still further aspect of the present invention, a computer program product causes a processor to perform: a receiving step of receiving a plurality of images obtained from a separate-pickup of an object performed such that parts of the images are overlapped; a first combining step of combining two images adjacent to each other in a first direction based on overlapping regions of two images adjacent to each other in the first direction; and a second combining step of combining two images adjacent to each other in a second direction based on overlapping regions of two images adjacent to each other in the second direction; wherein the first combining step is performed first and then the second combining step is performed when the plurality of images can be combined at the first combining step whereas the second combining step is performed first and then the first combining step is performed when the plurality of images cannot be combined at the first combining step.
According to still further aspect of the present invention, a computer program product causes a processor to perform: a first receiving step of receiving a plurality of images obtained from a separate-pickup of an object performed such that parts of images are overlapped; a first combining step of combining two adjacent images based on overlapping regions of the two adjacent images; a second receiving step of receiving an image including a feature point common to the two adjacent images when the two adjacent images cannot be combined at the first combining step; and a second combining step of combining the two adjacent images based on the image received at the second receiving step.
According to still further aspect of the present invention, an image processing method of combining at least three images includes the steps of: determining whether a first image and a second image can be combined based on an overlapping region or not, the overlapping region being a region in which the first and second images overlap; deciding whether to first combine the first image and the second image or to first combine the second image and a third image based on a result of determination; and combining images based on the decision.
According to still further aspect of the present invention, a computer program product employed to combine at least three images, causes a processor to perform the steps of: determining whether a first image and a second image can be combined based on an overlapping region or not, the overlapping region being a region in which the first and second images overlap; deciding whether to first combine the first image and the second image or to first combine the second image and a third image based on a result of determination; and combining images based on the decision.
According to still further aspect of the present invention, an image processing method of combining at least three images includes the steps of:
determining whether two images can be combined with each other based on an overlapping region, the overlapping region is a region in which the two images overlap with each other; deciding an order of combining based on a result of determination; and combining images based on a decided order.
According to still further aspect of the present invention, a computer program product employed to combine at least three images, causes a processor to perform the steps of: determining whether two images can be combined with each other based on an overlapping region, the overlapping region being a region in which the two images overlap with each other; deciding an order of combining based on a result of determination; and combining images based on a decided order.
According to the present invention, image processing devices, image processing methods and computer program products allowing the accurate combining of two images even when a common feature point does not exist in a region where two adjacent images overlap can be provided.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.